1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/CHANGES-92f.txt Thu Sep 16 12:20:38 1993 +0200
1.3 @@ -0,0 +1,40 @@
1.4 +**** Isabelle-92f : a faster version of Isabelle-92 ****
1.5 +
1.6 +Isabelle now runs faster through a combination of improvements: pattern
1.7 +unification, discrimination nets and removal of assumptions during
1.8 +simplification. Classical reasoning (e.g. fast_tac) runs up to 30% faster
1.9 +when large numbers of rules are involved. Rewriting (e.g. SIMP_TAC) runs
1.10 +up to 3 times faster for large subgoals.
1.11 +
1.12 +The new version will not benefit everybody; unless you require greater
1.13 +speed, it may be best to stay with the existing version. The new changes
1.14 +have not been documented properly, and there are a few incompatibilities.
1.15 +
1.16 +THE SPEEDUPS
1.17 +
1.18 +Pattern unification is completely invisible to users. It efficiently
1.19 +handles a common case of higher-order unification.
1.20 +
1.21 +Discrimination nets replace the old stringtrees. They provide fast lookup
1.22 +in a large set of rules for matching or unification. New "net" tactics
1.23 +replace the "compat_..." tactics based on stringtrees. Tactics
1.24 +biresolve_from_nets_tac, bimatch_from_nets_tac, resolve_from_net_tac and
1.25 +match_from_net_tac take a net, rather than a list of rules, and perform
1.26 +resolution or matching. Tactics net_biresolve_tac, net_bimatch_tac
1.27 +net_resolve_tac and net_match_tac take a list of rules, build a net
1.28 +(internally) and perform resolution or matching.
1.29 +
1.30 +The tactical METAHYPS, which allows a subgoal's hypotheses to be taken as a
1.31 +list of theorems, has been extended to handle unknowns (although not type
1.32 +unknowns). The simplification tactics now use METAHYPS to economise on
1.33 +storage consumption, and to avoid problems involving "parameters" bound in
1.34 +a subgoal. The modified simplifier now requires the auto_tac to take an
1.35 +extra argument: a list of theorems, which represents the assumptions of the
1.36 +current subgoal.
1.37 +
1.38 +OTHER CHANGES
1.39 +
1.40 +Apart from minor improvements in Pure Isabelle, the main other changes are
1.41 +extensions to object-logics. HOL now contains a treatment of co-induction
1.42 +and co-recursion, while ZF contains a formalization of equivalence classes,
1.43 +the integers and binary arithmetic. None of this material is documented.

2.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
2.2 +++ b/COPYRIGHT Thu Sep 16 12:20:38 1993 +0200
2.3 @@ -0,0 +1,21 @@
2.4 +ISABELLE COPYRIGHT NOTICE, LICENCE AND DISCLAIMER.
2.5 +
2.6 +Copyright (C) 1992 by the University of Cambridge, Cambridge, England.
2.7 +
2.8 +Permission to use, copy, modify, and distribute this software and its
2.9 +documentation for any non-commercial purpose and without fee is hereby
2.10 +granted, provided that the above copyright notice appears in all copies and
2.11 +that both the copyright notice and this permission notice and warranty
2.12 +disclaimer appear in supporting documentation, and that the name of the
2.13 +University of Cambridge not be used in advertising or publicity pertaining
2.14 +to distribution of the software without specific, written prior permission.
2.15 +
2.16 +The University of Cambridge disclaims all warranties with regard to this
2.17 +software, including all implied warranties of merchantability and fitness.
2.18 +In no event shall the University of Cambridge be liable for any special,
2.19 +indirect or consequential damages or any damages whatsoever resulting from
2.20 +loss of use, data or profits, whether in an action of contract, negligence
2.21 +or other tortious action, arising out of or in connection with the use or
2.22 +performance of this software.
2.23 +
2.24 +